Variable-sweep wing aerial vehicle with vtol capabilites

ABSTRACT

A variable-sweep wing VTOL (vertical take-off and landing) aerial vehicle with distributed propulsion adapted for VTOL flight and horizontal flight includes a fuselage, a pair of symmetrical swiveling canards extending outward from forward portion of the fuselage, a pair of first symmetrical wings extending outward from the upper-rear portion of the fuselage and a pair of second symmetrical wings extending outward from the lower-rear portion of the fuselage. The first and second wings are spaced apart longitudinally and vertically. The pylon joins the first wing and second wing at the tip to from the box-wing. The wings can transition between VTOL mode or airplane mode. The wings are mounted with rotors for propulsion. Moreover, at the trailing edge of the wings, the blown flap work as blown lift system for both VTOL flight or STOL flight. Finally, the fuselage mounted pusher rotor provides propulsive thrust for horizontal flight.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The disclosed invention relates to a variable-sweep wing aerial vehicle adapted for VTOL (vertical take-off and landing), and more specifically to the positional configuration of the variable-sweep wing suitable for VTOL, STOL (short take-off and landing) and airplane horizontal flight. Moreover, the propulsion system includes wing mounted propulsors and fuselage mounted rear propulsor.

2. Description of Related Art

The helicopter is an essential modern air transportation vehicle. Technically, helicopter with rotary wing is also referred as “rotorcraft” or “rotary wing vehicle”. The rotary wing is commonly referred as “rotor”. In general, rotary wing consists of propeller comprising of a plurality of blades. The rotary movement of the blades is the air mover to generate thrust. The rotary wing permits the helicopter to take-off and land vertically without the presence of a run way. Disadvantageously, helicopter with fossil fuel engine is associated with expensive operational cost, undesirable high level of noise and carbon emission.

As the traffic is increasing heavy in the global urban area, an affordable electrical VTOL vehicle is the solution to avoid road congestion. Without traffic delay, an electrical VTOL vehicle can also operate as law enforcement vehicle, ambulance and medical cargo transporter. A new term UAM (urban air mobility) is adopted for this new type of aerial transportation.

The most common propulsion design of modern VTOL vehicle is classified in the following categories: rotorcraft, tilt wing, tilt pod, lift with cruise or gyrocopter. The energy required for VTOL flight is significantly higher than the energy required for a fix wing airplane to maintain forward flight. Advantageously, modern electrical VTOL vehicle with fixed-wing also has the capability to transition to airplane mode for horizontal flight. During airplane mode, the VTOL vehicle is depending on the forward speed to generate lift from the fixed wings. One of the disadvantages is the independent VTOL propulsion system and cruise propulsion system. Consequently, during airplane mode, the VTOL propulsion system acts as dead weight and creates aerodynamic drag. The solution is to design a long-range VTOL vehicle with a common propulsion system for all flight modes.

The blown flap or blown wing is a high lift device used on traditional fixed wing airplane to achieve STOL. However, in theory, the blown flap or blown wing cannot achieve VTOL capability due to the aftward directed propulsive thrust. A new solution is needed to enable the blown flap and blown wing architecture for VTOL vehicle.

Traditionally aircraft wing suffers from significant loses of lift efficiency at the tip of the wings, due to the occurrence of vortex. As a result, winglet, sharklet and box-wing design is introduced to improve lift efficiency. The preferable solution is box-wing design to eliminate the occurrence of vortex and strengthen the wing.

Another challenge for VTOL vehicle is to operate safety near the ground, by maintaining safe distance between the wing and rotating blade to a person or an object. Furthermore, the fixed wing VTOL vehicle needs to minimize the footprint on ground for parking and taxiing. The ideal solution is to design a VTOL capable vehicle with minimized footprint on ground.

BRIEF SUMMARY OF THE INVENTION

An aerial vehicle with different configuration of the variable-sweep wing is adapted for VTOL (vertical take-off and landing) and airplane horizontal flight. The propulsion system of the aerial vehicle includes the distributed propulsion units mounted to the variable-sweep wing and the pusher propulsion unit mounted to the fuselage. The aerial vehicle uses the different configuration of its wing to adapt the propulsive thrust of the distributed propulsion units for VTOL and airplane horizontal flight.

In one embodiment of the variable-sweep wing aerial vehicle comprising a longitudinal extended fuselage, a pair of swiveling canards extended transverse from opposed sides of the fuselage, a vertical stabilizer extended vertical from the fuselage, a rear ducted fan secured to the fuselage, a pair of transverse wings secured to the opposed sides of the fuselage in a first configuration, a pair of longitudinal wings secured to the opposed sides of the fuselage in a second configuration, a plurality of ducted fan secured to the upper surface of the wing, and blown flap secured to the trailing edge of the wing.

In another embodiment of the variable-sweep wing aerial vehicle comprising a longitudinal extended fuselage, a pair of swiveling canards extended transverse from opposed sides of the fuselage, a vertical stabilizer extended vertical from the fuselage, a rear ducted fan secured to the fuselage, a pair of transverse wings secured to the opposed sides of the fuselage in a first configuration, a pair of longitudinal wings secured to the opposed sides of the fuselage in a second configuration, a plurality of unducted fan secured to wing, and blown flap secured to the trailing edge of the wing.

BRIEF DESCRIPTION OF THE DRAWINGS

Regarding the invention disclosure, the feature and advantage of the invention are particularly pointed and distinctly claimed in the claims. Detailed description and methods are given to provide further comprehension of the functionality of the invention. It should be observed that three mutual orthogonal directions X, Y, and Z are shown in some of the FIGURES. The first direction X is said to be “longitudinal”, and the forward side is referenced to be positive. Rotational movement around the longitudinal axis is said to be “roll”. The second direction Y is said to be “transverse”, and the port side is referenced to be positive. And the Y plane is referenced as centerline of the vehicle. Rotational movement around the transverse axis is said to be “pitch”. Finally, the third direction Z is said to be “vertical”, and the up side is referenced to be positive. Rotational movement around the vertical axis is said to be “yaw”. Furthermore, an object in motion is shown in dash line.

FIG. 1 is a perspective view of the embodiment of the variable-sweep wing aerial vehicle depicting the horizontal flight configuration.

FIG. 2 is a side view of the variable-sweep wing aerial vehicle of FIG. 1 .

FIG. 3 is a rear view of the variable-sweep wing aerial vehicle of FIG. 1 .

FIG. 4 is a plan view of the variable-sweep wing aerial vehicle of FIG. 1 .

FIG. 5 is a plan view of another embodiment of the variable-sweep wing aerial vehicle depicting the VTOL flight configuration.

FIG. 6 is a rear view of the variable-sweep wing aerial vehicle of FIG. 5 .

FIG. 7 shows a cross-sectional view of an embodiment of the propulsion system of FIG. 1 .

FIG. 8 shows a cross-sectional view of an embodiment of the propulsion system of FIG. 5 .

FIG. 9 is a perspective view of another embodiment of variable-sweep wing aerial vehicle with an alternative propulsion system.

FIG. 10 is a rear view of the variable-sweep wing aerial vehicle of FIG. 9 .

FIG. 11 shows a cross-sectional view of a first embodiment of the propulsion system of FIG. 9 .

FIG. 12 shows a cross-sectional view a second embodiment of the propulsion system of FIG. 9 .

FIG. 13 shows a cross-sectional view of a third embodiment of the propulsion system of FIG. 9 .

DETAILED DESCRIPTION OF THE INVENTION

Advantageously, VTOL (vertical take-off and landing) vehicle can operate without a runway. However, an aerial vehicle operating in VTOL mode requires significantly higher energy than an airplane with fixed wing to maintain forward flight. Therefore, the usefulness of VTOL vehicle is limited to short-range flight. Modern VTOL vehicle is commonly designed with electrical power plant. In order to reduce the weight of electrical energy storage, a viable VTOL vehicle can adapt to airplane mode for long range forward fight. In the disclosure of the invention, the technical term ducted fan is referred as the rotor wrapped inside a nacelle and the technical term unducted fan is referred as the rotor without nacelle. Furthermore, rotor is a rotating device to generate thrust by moving air.

FIGS. 1 to 4 illustrate the first embodiment 100 of the variable-sweep wing aerial vehicle in airplane mode. FIG. 2 shows the side view of the embodiment 100 comprises of a longitudinal extended fuselage 101. The nose portion of the fuselage 101 is provided with the nose landing gear or landing pad 102. The forward portion of the fuselage 101 is provided with the swiveling canard 103. The belly portion of the fuselage 101 is provided with the main landing gear or landing pad 104. The side portion of the fuselage 101 is provided with the upper door 105 and lower door 106. The rear portion of the fuselage 101 is provided with the transverse extended upper wing 107 and transverse extended lower wing 108. The upper wing 107 and lower wing 108 are joined at the tip by the pylon 109 to from the box-wing structure. The upper-rear portion of the fuselage 101 is provided with the vertical stabilizer 110 and rudder 111. The tail portion of the fuselage 101 is provided with the rear ducted fan 112. It can be observed from FIG. 3 , that the upper surface of the upper wing 107 is provided with a plurality of ducted fans 113 and blown flap 114. The upper surface of the lower wing 108 is provided with a plurality of ducted fans 115 and blown flap 116. The rotary movement of the rotor mounted within the ducted fan 113 and 115 is independently driven by at least one motor. As a result of the rotary movement, thrust is generated by the rotors. It can be observed from FIG. 4 , that upper wing 107 and lower wing 108 are offset longitudinally, this stagger layout reduces aerodynamic interference effects between the two main wings. FIG. 7 shows a cross-sectional view of one aspect of the upper wing 107 and lower wing 108, ducted fan 118, rotor 119 and blown flap 120 stowed in the horizontal position. In this aspect, the thrust of rotor 119 generates airfoil lift from the wing and horizontal propulsive thrust. The transition of the vehicle from VTOL mode as shown in embodiment 500 to airplane mode as shown in embodiment 100 is described in the following sections. After airborne from VTOL mode, the rear ducted fan 112 provides the initially forward propulsive thrust during airplane mode. Firstly, as the vehicle reaches faster forward speed, the upper wing 107 and lower wing 108 sweep to the airplane mode position as shown in embodiment 100. Secondly, as the vehicle reaches the cruising speed, the blown flap 114 and 116 return to the horizontal stowed position. As a result of the cruising air speed, airfoil lift is generated by the upper wing 107, lower wing 108 and swiveling canard 103. The horizontal flight thrust can be provided by a combination of the ducted fan 113, 115 and rear ducted fan 112. The rear ducted fan 112 is known as the Boundary Layer Ingestion propulsor identified by NASA. Naturally, the flight control of the vehicle in airplane mode is consisting of swiveling canard 103, rudder 111 and blown flap 114. The airfoil lift and horizontal propulsive thrust are proportional to the speed of the rotor. In detail, the blown flap 114 or 116 is also used as flight control aileron. In addition, the modulation of the speed of the rotor within ducted fan 113 and 115 on the opposed sides of said fuselage 101, creates a horizontal thrust vector and vertical lift vector for flight control. In case of mechanical failure of the variable-sweep wings actuating system, the vehicle in embodiment 100 can achieve a short landing with the aid of the blown flap 114 and 116.

FIGS. 5 to 6 illustrate the second embodiment 500 of the variable-sweep wing aerial vehicle in VTOL mode. The operation of the variable-sweep wing aerial vehicle in VTOL mode includes vertical taking-off, vertical landing, hovering, and vertical flight. It can be observed from FIG. 5 , that the span of the upper wing 107 and lower wing 108 is rotated to align with the longitudinal axis of the fuselage 101. The rotation movement of the wings is provided by the actuating system 117. Moreover, the upper door 105 and lower door 106 are in the open position. It can be observed from FIG. 6 , that blown flap 114 and blown flap 116 are deployed in the downward position. FIG. 8 shows a cross-sectional view of a second aspect of the upper wing 107, lower wing 108, ducted fan 118, rotor 119 and blown flap 120 deployed in the downward position. This combination of ducted fan 118 and blown flap 120 is known as the upper surface blown flap. As a result of the rotary movement of the rotor within the ducted fans, a lateral propulsive thrust is produced by the movement of air across the chord of the wings. The lateral propulsive thrust of the portside ducted fans and starboard ducted fans are cancelled out. This feature maintains the vehicle motionless on the horizontal plane. The blown flap 120 are deployed downward to convert partially the lateral propulsive thrust of the rotor 119 into blown lift. Moreover, the movement of air generates airfoil lift from the upper wing 107 and lower wing 108. Naturally, the VTOL fight is depending on the net vertical force consist of airfoil lift from the wing and blown lift from the blown flap. The airfoil lift and blown lift are proportional to the speed of the rotor. The modulation of the speed of the rotors provides the capability to maneuver. Firstly, the balance of the longitudinal and transverse vertical force vector allows the vehicle to fly levelly up and down in the Z axis. Secondly, an unbalance of the longitudinal vertical force vector allows the vehicle to pitch forward or aft, which allows the vehicle to fly forward and aftward. Thirdly, an unbalance of the transverse vertical force vector allows the vehicle to roll sideward, which allows the vehicle to fly side way. The yaw directional control is achieved by the unbalance of the lateral propulsive thrust vector.

FIGS. 9 to 13 , shows the embodiment 900 of the variable-sweep wing aerial vehicle. FIG. 9 shows the perspective view of the embodiment 900, comprises of a plurality of unducted fan 903 and 904 integrated withing the cavity of the upper wing 901 and lower wing 902. The plurality of unducted fan 903 and 904 is a propulsion system variant of the ducted fan 113 and ducted fan 115 of embodiment 100. The operation of embodiment 900 is the same as embodiment 100. In FIG. 10 , it can be observed, that the dash circle representing the rotor disc area of the plurality of unducted fan 903 and 904. FIG. 11 shows a cross-sectional view of one aspect of the upper wing 901, lower wing 902, unducted fan 905 and blown flap 908. Furthermore, it can be observed that the rotor of the unducted fan 905 is in the stowed position and the blown flap 908 is stowed in the horizontal position. The unducted fan 905 comprises of a rotor with two blades or a stacked corotation propeller of two blades. A stacked corotation propeller comprising of two rotors in a co-axial arrangement. Furthermore, the two rotors are rotating in the same direction and each rotor is driven by at least one independent motor. In the stowed rotor position, the blades are aligned horizontally to the span of the wing. More specifically, the blades do not protrude outside of the wing. Moreover, a plurality of sliding panel 906 and 907 closes the aerodynamic gap of the upper wing 901 and lower wing 902. As a result, drag is reduced during horizontal flight. FIG. 12 shows a cross-sectional view of a second aspect of the upper wing 901, lower wing 902, unducted fan 905 and blown flap 908. Furthermore, it can be observed from the view that the rotor of unducted fan 905 is in the rotating state and the blown flap 908 is stowed in the horizontal position. The plurality of sliding panel 906 and 907 on the upper wing 901 and lower wing 902 are in the open position. As a result, the rotor of unducted fan 905 is allow to rotate. Naturally, with the wing in the airplane mode configuration, the rotation of the rotor moves air from the leading edge to the trailing edge of the wing to generate vertical airfoil lift from the wing and aftward horizontal propulsive thrust. FIG. 13 shows a cross-sectional view of a third aspect of the upper wing 901, lower wing 902, unducted fan 905 and blown flap 908. Furthermore, it can be observed from the view that the rotor of the unducted fan 905 is in the rotating state and blown flap 908 is deployed in the downward position. Moreover, the plurality of sliding panel 906 and 907 on the upper wing 901 and lower wing 902 are in the open position. The thrust of the rotor is partially converted to a vertical blown lift vector by the deployed blown flap 908. This combination of unducted fan and downward blown flap is known as the vectored slipstream. In one configuration of the wing positioned in the airplane mode, the vertical airfoil lift from the wing and vertical blown lift from the blown flap allow the vehicle to achieve STOL flight. In another configuration of the wing positioned in the VTOL mode, the vertical airfoil lift from the wing and vertical blown lift from the blown flap allow the vehicle to achieve VTOL flight.

Naturally, there are numerous variations, modifications and configurations which may be made hereto without departing from the scope of the disclosure invention. It should be understood that the embodiments are for illustrative and explanatory purpose and it is not conceivable to identify exhaustively all possible embodiments. In particular, it is important to observe that the described invention relates to a variable-sweep wing aerial vehicle with transformable main wings adapted for air plane mode as shown in embodiment 100 and VTOL mode as shown in embodiment 500. In the VTOL mode, a plurality of rotor moves air over the wing to generated airfoil lift. Secondly, the lateral thrust of the plurality of rotor is partially converted to a vertical blown lift vector by the deployed blown flaps on the trailing edge of the wings. The remaining lateral thrust vector is a net zero force acting on the vehicle. Advantageously, the vehicle benefits from both airfoil lift and blown lift for vertical taking-off, vertical landing, hovering, and vertical flight. Moreover, lateral thrust vector can be used to adjust the vehicle directional heading along the yaw axis. The smaller footprint of embodiment 500 is beneficial for ground operation. The design of the box-wing benefits from an improvement of structural strength, fatigue strength and load carrying strength. Furthermore, the aerial vehicle with variable-sweep wing in horizontal flight configuration as shown in embodiment 100 can fly, take-off and land like a conventional fixed-wing airplane. Nevertheless, the invention is applicable to any VTOL vehicle of arbitrary weight, such as a light drone to a large tonnage vehicle. 

What is claimed is:
 1. A variable-sweep wing aerial vehicle adapted for VTOL flight comprising: a longitudinal extended fuselage; a pair of swiveling canards extended transverse from opposed sides of the fuselage; a vertical stabilizer extended vertical from the fuselage; a rear ducted fan secured to the fuselage; a variable-sweep wing secured to the fuselage, said variable-sweep wing comprising: a port side wing structure portion, said port side wing structure comprising: a port side upper wing; and a port side lower wing; and a pylon joined to the tip of said port side upper wing and said port side lower wing; and a starboard side wing structure portion, said starboard side wing structure comprising: a starboard side upper wing; and a starboard side lower wing; and a pylon joined to the tip of said starboard side upper wing and said starboard side lower wing; a plurality of ducted fan secured on the upper surface along the span of said port side upper wing; a plurality of ducted fan secured on the upper surface along the span of said port side lower wing; a plurality of ducted fan secured on the upper surface along the span of said starboard side upper wing; a plurality of ducted fan secured on the upper surface along the span of said starboard side lower wing; a blown flap secured to the trailing edge of said port side upper wing; a blown flap secured to the trailing edge of said port side lower wing; a blown flap secured to the trailing edge of said starboard side upper wing; a blown flap secured to the trailing edge of said starboard side lower wing.
 2. A variable-sweep wing aerial vehicle as set forth in claim 1, wherein said port side wing structure and starboard side wing structure can rotate symmetrical along the vertical center plane of said fuselage, and the wing span orientation of opposed wings are extended transverse from said fuselage is the first configuration adapted for horizontal flight.
 3. A variable-sweep wing aerial vehicle as set forth in claim 1, wherein said port side wing structure and starboard side wing structure can rotate symmetrical along the vertical center plane of said fuselage, and the wing span orientation of opposed wings are extended along the longitudinal axis of said fuselage is the second configuration with reduced planar footprint adapted for VTOL (vertical taking-off and landing), hovering, and vertical flight.
 4. A variable-sweep wing aerial vehicle as set forth in claim 1, wherein said plurality of ducted fans moves air from the leading edge to the trailing edge of the wing to generate vertical airfoil lift and propulsive thrust perpendicular to the span of the wing.
 5. A variable-sweep wing aerial vehicle as set forth in claim 1, in the first configuration, wherein said blown flap is an upper surface blown flap system to convert the propulsive thrust of said plurality of ducted fan to blown lift thrust for STOL (short take-off and landing).
 6. A variable-sweep wing aerial vehicle as set forth in claim 1, in the second configuration, wherein said blown flap is an upper surface blown flap system to convert the propulsive thrust of said plurality of ducted fan to blown lift thrust for VTOL (vertical taking-off and landing), hovering and vertical flight.
 7. A variable-sweep wing aerial vehicle as set forth in claim 1, in the first configuration, wherein said plurality of ducted fan with modulated output thrust generates the vertical lift vector and longitudinal thrust vector to maneuver the vehicle.
 8. A variable-sweep wing aerial vehicle as set forth in claim 1, in the second configuration, wherein said plurality of ducted fan with modulated output thrust generates the vertical lift vector and transverse thrust vector to maneuver the vehicle.
 9. A variable-sweep wing aerial vehicle as set forth in claim 1, wherein said blown flap is used as flight control surface in horizontal flight.
 10. A variable-sweep wing aerial vehicle as set forth in claim 1, wherein said rear ducted fan provides propulsive thrust for horizontal flight.
 11. A second variable-sweep wing aerial vehicle adapted for VTOL flight comprising: a longitudinal extended fuselage; a pair of swiveling canards extended transverse from opposed sides of the fuselage; a vertical stabilizer extended vertical from the fuselage; a rear ducted fan secured to the fuselage; a variable-sweep wing secured to the fuselage, said variable-sweep wing comprising: a port side wing structure portion, said port side wing structure comprising: a port side upper wing; and a port side lower wing; and a pylon joined to the tip of said port side upper wing and said port side lower wing; and a starboard side wing structure portion, said starboard side wing structure comprising: a starboard side upper wing; and a starboard side lower wing; and a pylon joined to the tip of said starboard side upper wing and said starboard side lower wing; a plurality of unducted fan secured within the cavity along the span of said port side upper wing; a plurality of unducted fan secured within the cavity along the span of said port side lower wing; a plurality of unducted fan secured within the cavity along the span of said starboard side upper wing; a plurality of unducted fan secured within the cavity along the span of said starboard side lower wing; a plurality of sliding panel on said port side upper wing; a plurality of sliding panel on said port side lower wing; a plurality of sliding panel on said starboard side upper wing; a plurality of sliding panel on said starboard side lower wing; a blown flap secured to the trailing edge of said port side upper wing; a blown flap secured to the trailing edge of said port side lower wing; a blown flap secured to the trailing edge of said starboard side upper wing; a blown flap secured to the trailing edge of said starboard side lower wing.
 12. A variable-sweep wing aerial vehicle as set forth in claim 11, wherein said port side wing structure and starboard side wing structure can rotate symmetrical along the vertical center plane of said fuselage, and the wing span orientation of opposed wings are extended transverse from said fuselage is the first configuration adapted for horizontal flight.
 13. A variable-sweep wing aerial vehicle as set forth in claim 11, wherein said port side wing structure and starboard side wing structure can rotate symmetrical along the vertical center plane of said fuselage, and the wing span orientation of opposed wings are extended along the longitudinal axis of said fuselage is the second configuration with reduced planar footprint adapted for VTOL (vertical taking-off and landing), hovering, and vertical flight.
 14. A variable-sweep wing aerial vehicle as set forth in claim 11, wherein said plurality of unducted fans moves air from the leading edge to the trailing edge of the wing to generate vertical airfoil lift and propulsive thrust perpendicular to the span of the wing.
 15. A variable-sweep wing aerial vehicle as set forth in claim 11, wherein said plurality of sliding panel closes the gap on the wing surface for reduction of aerodynamic drag when said plurality of unducted fan is not operating, and wherein said rear ducted fan provides propulsive forward thrust.
 16. A variable-sweep wing aerial vehicle as set forth in claim 11, in the first configuration, wherein said blown flap is a vectored slipstream system to convert the propulsive thrust of said plurality of unducted fan to blown lift thrust for STOL (short take-off and landing).
 17. A variable-sweep wing aerial vehicle as set forth in claim 11, in the second configuration, wherein said blown flap is a vectored slipstream system to convert the propulsive thrust of said plurality of unducted fan to blown lift thrust for VTOL (vertical taking-off and landing), hovering and vertical flight.
 18. A variable-sweep wing aerial vehicle as set forth in claim 11, in the first configuration, wherein said plurality of unducted fan with modulated output thrust generates the vertical lift vector and longitudinal thrust vector to maneuver the vehicle.
 19. A variable-sweep wing aerial vehicle as set forth in claim 11, in the second configuration, wherein said plurality of unducted fan with modulated output thrust generates the vertical lift vector and transverse thrust vector to maneuver the vehicle.
 20. A variable-sweep wing aerial vehicle as set forth in claim 11, wherein said blown flap is used as flight control surface in horizontal flight. 